Hydraulic torque converters used in connection with internal combustion engines in order to transfer torque from the engine to the transmission are known in the art.
Torque converters of the general type to which the present invention is applicable are, for example, shown in U.S. Pat. No. 6,142,272 or U.S. 2012/0266589, both of which are assigned to the Assignee of the present invention. In such torque converters, typically the torque converter housing is connected to the internal combustion engine for torque input, and includes a pump with blades on an interior thereof which can be hydraulically coupled with turbine blades connected to an associated turbine located within the torque converter. The turbine is supported via a turbine hub, which can be an integral part of the turbine or a separately connected turbine hub, typically centered about the input shaft for the transmission. The turbine hub is coupled to the input shaft via a damper assembly which includes a damper flange having a sleeve portion with inner teeth or splines which engage the input shaft. In U.S. 2012/0266589, the turbine hub is centered by riding on the sleeve portion of the damper flange and torque is transferred from the turbine to the damper flange via damper springs located between a cover plate connected to the turbine hub and the damper flange. A lock up assembly can also be provided for direct transfer of torque through additional damper springs to the damper flange. In such arrangements, a stator is also typically located between the pump and turbine blades.
FIGS. 1 and 2 show an enlarged view of one known prior art torque converter 10 with the turbine hub 12 connected to a turbine body 13, preferably via fasteners 26, such as rivets. The turbine hub 12 is centered by riding on the sleeve portion 20 of the damper flange 18. Blades 15 are connected to the turbine body 13. Here, torque is transferred from the turbine 13 via its hub 12 to a cover plate 14 fixed to the turbine hub 12, and into the damper flange 18 via spring 16 of the damper assembly. In this case, in order to transfer axial loads from the turbine hub 12 to the damper flange 18, a bulge or stop 24 is required on the sleeve portion 20, as shown, that the turbine hub thrusts against. However, this bulge or stop 24 is typically formed by a coining operation which adds expense to the manufacturing process.
Other arrangements for piloting and transmitting axial thrust into the damper flange require additional stamped components or a secondary feature in the damper flange. In the illustrated arrangement, the contact surface of the hub 12 for axial thrusting against the damper flange 18 as well as the receiving portion of the damper flange 18 generally require machining due to the tolerances and geometry after forming the damper flange. Further, coining the stop 24 on the sleeve portion 20 of the damper flange has been found to negatively impact the inside diameter of the sleeve portion typically formed as an extruded neck during the stamping process for the damper flange 18.
Accordingly, the drawbacks associated with many of these known arrangements include complex assembly as well as higher costs. Additionally, given the current drive toward efficiency, it would be desirable to provide for reduced weight and part count, as well as simplifying assembly of the torque converter.